JPS61109388A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To make a reproducing signal continue easily and satisfactorily by installing a starting indentifying signal at the tip of respective segmetns. CONSTITUTION:A video signal is recorded through a recording circuit 2, a switch 4, an FM modulating circuit 5 and a head 6 to a disk D. On the other hand, a sound signal is A/D converted 13 and stored in a memory 14, and thereafter, the signal is read and D/A converted 15. The writing to the memory 14 is executed by the output of an oscillator 21, the reading is executed by the output of the high frequency of an oscillator 21, and the sound signal is compressed by the time base. A start identifying signal and an end identifying signal are inserted before and after the compressed sound signal at a mixing circuit 16 and supplied to a modulating circuit 5. At the time of reproduction, the video signal of the signal FM-demodulated 32 is stored in reproducing circuit 34, and the sound signal is A//D-converted 42 and stored in a memory 43, and thereafter, they are D/A-converted and supplied to a decoder 45. At such a time, respective start/end identifying signals are detected 56, and the sound signal is extended and continued at the time of the reading from the memory 43.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to recording and reproducing audio signals using a still image recording and reproducing device such as a so-called electronic still camera device.

[Conventional technology]

An electronic still camera device has been proposed that has a 114-image device such as COD and records one field or one frame of residential and leisure signals on a magnetic disk (Utility Model 5).
7-197,021, etc.).

In other words, in such a device, the video signal from the imaging device is extracted by gated one field or one frame at the time of arbitrary shutter operation, and this signal is divided into one field and one annular track. recorded on a magnetic disk. Note that one frame of signal is recorded using two tracks. Therefore, in this device, a video signal of a still image can be formed by repeatedly reproducing one track or two tracks alternately.

It has been proposed to provide such devices with the additional possibility of recording audio signals. To do this, for example, the audio signal can be compressed on the time axis using digital signal processing technology, the frequency range of the audio signal can be reduced to the video signal band, and the audio signal can be recorded using the same recording system as the video signal. is possible.

In this case, for example, by compressing the time axis of an audio signal up to 5 kHz by a factor of 600, it is possible to create a signal with a video band of 3 MHz. And in this case, 1
During the field period (1/60 second), 600 times that amount, about 10
It can record audio signals for seconds.

However, in this case, in order to perform the above-mentioned digital processing on, for example, a 10 second audio signal, an extremely large capacity memory device is required. So, for example, 10 seconds is 4
It is possible to reduce the capacity of the memory device by dividing the data into equal parts and digitally processing them in 2.5 second increments.
It becomes extremely difficult to maintain the continuity of the above-mentioned segments during playback.

In addition, if you want to record an audio signal for a longer time than, for example, 10 seconds as mentioned above, you will have to record across multiple tracks, but even in that case, it is extremely difficult to maintain track continuity during playback. be.

[Problem that the invention seeks to solve]

Conventional devices were constructed as described above. However, with this device, when recording is segmented or when recording is performed across multiple tracks,
There was a problem in that it was extremely difficult to maintain continuity during playback.

[Means for solving problems]

The present invention provides a recording and reproducing apparatus in which one field of video signals is sequentially recorded concentrically as one track, and an audio signal is compressed on the time axis (22) (25).
and record it on the track marked in - instead of the above video signal (6
), the continuous audio signal is divided into a plurality of segments using a memory (14) whose length is rectangular than the time during which the audio signal is continuously recorded, and the time axis is compressed and recorded. and this compressed each above segment 1
A start identification signal SID is provided at the leading end of the - signal, and the time axis is compressed using the start identification signal STD during playback.

This is a recording/reproducing device which expands and serializes (52) (55) the received signal.

[Effect]

According to the above-mentioned apparatus, since the start identification signal is provided at the tip of each segment, it is possible to use this signal to very easily and efficiently make the reproduced signal continuous. Note that continuity between tracks can also be performed in the same way as between two consecutive segments.

〔Example〕

FIG. 1 shows a block diagram of a recording system, and FIG. 2 shows a block diagram of a reproduction system.

In FIG. 1, a video signal is supplied to an input terminal (11), converted into a predetermined recording signal by a recording circuit (2), and passed through a pre-emphasis circuit (3) with non-linear characteristics and a changeover switch (4) to an FM modulation circuit ( 5), and recorded on the disk D by the magnetic head (6) as an FM signal.

The audio signal is also supplied to the input terminal (11) and is supplied to the AD conversion circuit (13) through the encoder circuit II (12) for noise reduction. This digitally converted signal is supplied to the memory device (14). 5kll again
The sampling signal of the audio signal in the band z is sent to the oscillator (21
), and this signal drives an AD conversion circuit (13) and a memory device (14).
is supplied to Furthermore, an oscillator (23) having an oscillation frequency 600 times that of the above-mentioned oscillator (21) is provided, and a signal from this oscillator (23) is supplied to the address counter (22). Further, a pulse related to the rotational phase of the disk from a magnetic piece provided at a predetermined portion of the disk D is detected by the pickup head (24), and this signal is supplied to the memory controller (25). For example, as shown in FIG. 3, the signal written in the memory device (14) every 2.5 seconds, which is divided into four equal parts of 10 seconds, is read out 600 times faster, and the timing is As shown in Figure 4,
The pulses related to the rotational phase from the head (24) are sequentially output at timings that are sequentially delayed in phase by 1/4 every 2.5 seconds.

This read signal is supplied to the DA conversion circuit (15). This conversion time [l! 8 (15) is supplied with a signal from the oscillator (23). This analog-converted signal is supplied to a pre-emphasis circuit (17) with linear characteristics through a mixing circuit (16), and this pre-emphasis circuit (
The signal from 17) is supplied to the FM modulation circuit (5) through the changeover switch (4), and recorded on the disk D by the magnetic head (6) as an FM signal.

In this circuit, a start identification signal S as shown in FIG.
TD and end identification signal EID are inserted into the time-base compressed audio signal before and after a predetermined time. Note that these identification signals are, for example, memory controller (25)
A signal from the identification signal generating circuit (26) is supplied to the identification signal generating circuit (26) and generated.

Here, the identification signal has a shape that can be distinguished from the audio signal.

That is, for example, in the circuit described above, the low frequency of the audio signal is limited to a predetermined value, so that a pulse with a width T1 longer than a pulse corresponding to a frequency of the predetermined value when compressed on the time axis can be distinguished.

For example, the start identification signal has positive polarity and its rising edge is used as a reference, and the end' identification signal has negative polarity and its rising edge is used as a reference.

Furthermore, in FIG. 2, there is a magnetic field (3
The signal reproduced in step 1) is supplied to the FM demodulation circuit (32). When the demodulated signal is a video signal, this signal is sent to a de-emphasis circuit (33) with non-linear characteristics.
, is taken out to the output terminal (35) through the reproducing circuit (34).

Further, when the demodulated signal is an audio signal, this signal is supplied to the AD conversion circuit (42) through a de-emphasis circuit (old) with linear characteristics. This digitally converted signal is supplied to the memory device (43). Further, an oscillator (51) having the same frequency as the above-mentioned oscillator (23) is provided, and a signal from this oscillator (51) is transmitted to the AD conversion circuit (42).
) and the address counter (52) that drives the memory device (43).
An oscillator (53) with a frequency equal to 1) is provided, and a signal from this oscillator (53) is sent to the address counter (52).
is supplied to Also, Pisokwa is equivalent to the above-mentioned He・yF (24).

The signal from Buhesod (54) is transmitted to the memory controller (5).
5). For example, an operation opposite to that shown in FIGS. 3 and 4 above is performed in the memory device (43
) is read out at a speed of 1/600.

This read signal is supplied to the DA conversion circuit (44). A signal from an oscillator (53) is supplied to this conversion circuit (44). This analog-converted signal passes through the noise reduction decoder circuit (45) to the output terminal (
46).

Furthermore, in this circuit, a de-emphasis circuit (41)
The output signal is supplied to an identification signal detection circuit (56). Here, this detection circuit (56) is configured as shown in FIG. 6, for example. In the figure, the de-emphasis circuit (41)
An input terminal (61) to which a signal is supplied is supplied to a differentiating circuit for detecting a falling edge (62), a differentiating circuit for detecting a rising edge (63), and a low-pass filter (64), respectively, as shown in FIG. 7A.

Signals as shown in B and C are extracted. A comparator circuit (65) in which the signal from the low-pass filter (64) (Fig. 7C) has a detection level indicated by broken lines a and b, respectively.
(66), and the signals shown in Fig. 7 and E are taken out. These signals form a NAND circuit (
67) (68) and the corresponding differentiation circuit (6
2) The signal from (63) is a NAND circuit (67)
(68). Therefore Nando times 1?8 (67)
From then on, as shown in FIG. 7F, the falling edge of the start identification signal SID is detected and taken out to the output terminal (69). Further, as shown in FIG. 7G, rising edges of the end identification signals IF and ID are detected from the NAND circuit 1i8 (6B) and taken out to the output terminal (70).

Then, by supplying these signals to the memory controller (55), when the fall of the start identification signal SID is detected, the sampling of the signal and the νF inclusion are performed after time T2 (not shown in FIG. 5). After that, writing is continued by a signal from the oscillator (51), and when the rising edge of the end identification signal EID is detected, writing is stopped. Furthermore, after that, a T3 minute memory device (43
) address is returned. By repeating this operation for each segment, a signal in which the audio signal portion is made continuous is written into the memory device (43).

In addition, in the case where an OHARA sub is provided for the audio signal between each segment in a double circuit, when returning the address of the memory device (43) mentioned above, the address of T3+α (overramp portion) should be returned. . This makes it possible to prevent discontinuities from occurring due to jitter components and the like.

Continuation across a plurality of tracks can also be performed in the same way using the above-mentioned circuit.

This is how audio signals are recorded and played back.
According to the above-mentioned apparatus, by providing the star purpose-specific signal, it is possible to serialize the reproduced signal extremely easily and satisfactorily.

〔Effect of the invention〕

According to the present invention, since a star purpose-specific signal is provided at the tip of each segment 1, it is possible to use this signal to extremely easily and efficiently serialize the reproduced signal.

[Brief explanation of drawings]

Figures 1 and 2 are configuration diagrams of an example of the present invention, and Figures 3 to 7.
rffl is a diagram for explaining the same. (11) is an input terminal, (13) (42) is an AD conversion circuit, (14) (/13) is a memory device, (15)
(44) is a DA conversion circuit, (25) (55) is a memory controller I roller, (26) is an identification signal generation circuit,
(46) is an output terminal, and (56) is an identification signal detection circuit.

Claims (1)

[Claims] In a recording and reproducing device in which one field of video signal is sequentially recorded concentrically as one track,
When compressing the audio signal on the time axis and recording it on the track instead of the video signal, the continuous audio signal is compressed into multiple pieces using a memory whose length is shorter than the time during which the audio signal is continuously recorded. The time axis compressed signal is divided into segments and recorded, and a start identification signal is provided at the leading end of the signal of each compressed segment, and the start identification signal is used during playback to record the time axis compressed signal. A recording and reproducing device that expands and serializes.